Modern spark ignited (SI) internal combustion engines are often equipped with a knock sensor for detecting spark knock. Upon detection of knock, which may be caused by poor quality fuel, an engine control system retards the angle of spark delivery to the engine. The amount of retard, which may be referred to as knock retard, may then be decremented after a predetermined amount of time. If the variable, such as poor quality fuel, which caused the spark knock has passed through the engine or otherwise dissipated, then the engine will continue to operate without knocking at the advanced spark angle.
While such a system provides protection from spark knock, the engine may operate with knock retard for an undesirable amount of time, even when the variable, such as poor quality gas, has long passed through the engine.